Just to give this perspective, visualize this: in order to hold around 160 million tons of CO2 (around 2.2 days worth of current global emissions), it would take a cylindrical bag measuring 100 meters in radius and several kilometers long. The obviously immense weight of the bag, as well as the pressure from the ocean, would contain the CO2 and prevent the bag from floating up. If you’re wondering where a gas-filled bag of this size might be located, it would sit 3 kilometers below the ocean’s surface. Just like in subterranean carbon sequestration, the CO2 would be pumped and moved via pipes to the bag.

Maybe it’s just us, but giant plastic bags filled with carbon dioxide, submerged in the oceans depths sounds like a recipe for disaster. What if one of those things leaks or explodes? And with that kind of deep-ocean pressure on a bag so large.. how would this really work?

Dr. Keith is set to speak at the Annual Conference of the American Association for the Advancement of Science that will be held on April of this year. Needless to say, it will be interesting to hear his thoughts on this project, as the details are obviously going to be incredibly important. After all, storing a bag of that size in the ocean bed is likely to do significant damage to that very fragile environment. Furthermore, issues of maintenance (just how do you maintain it?), and how to prevent rupture, are significant problems that need to be worked out.+ Into the Abyss: Deep-sixing Carbon

The best way to deal with all the CO2 would be to plant a whole lot of trees, then cut them down and either
A) build something with them (houses, furniture)
B) stick them underwater or submersed in artificial bogs
That way they won't rot and release the CO2 back into the atmosphere again.
It is also the way that nature had sequestered all that carbon in the first place.. that gave us fossil fuels.

Good lord you people will bite at anything, won't you? If you want carbon sequestration in the ocean, dump some powdered iron in, the alga bloom will take up tons of CO2, and it will certainly be cheaper and more effective than this hair-brained bag scheme.

Have a look at the "biochar" technologies being developed around the world, as carbon-negative energy generation and carbon sequestration. These offer prospects (proven over a few millennia already in the Amazon) for soil regeneration rather than suffocation of fragile deep water ecosystems. A good starting place would be the International Biochar Initiative at biochar (dot) org. It's also an open-sourced international research effort with an agenda to deliver positive results as widely as possible. Quite refreshing against the background of denial, quick-fixes, quick bucks and more that is sprouting up around climate response.

I live in Calgary where Dr. Keith does his research. He is actually a very clever and pragmatic scientist, very much not in the pocket of the oil companies. Another of his research projects is the development of a simple and cost-effective method of absorbing carbon dioxide directly from the atmosphere to "sequester" the gas away in a chemically inert solid. Good stuff.
Like I said, Dr. Keith is a pragmatist. I'm sure that he's well aware of the potential problems of deep sea storage of CO2, but these risks have to be weighed against the the risks of having CO2 gas floating around in the atmosphere. The likelihood of the world continuing to use fossil fuels is very high...even to the point of exhaustion of these resources. The greenhouse gases from burning all of these fossil fuels have to go "somewhere" besides the atmosphere or we will face global-mean-temperature rise of between 1 to 5 degrees C. One degree might not be so disruptive, but 5 degrees would likely be catastrophic, if only for the sheer number of environmental refugees that would be displaced. Dr. Keith proposes a way of keeping CO2 out of the atmosphere, thus avoiding catastrophic changes to the surface climate that could put many many species at risk of extinction. This will probably be damaging to the flora and fauna of the deep ocean, but this might be a better option than letting the CO2 hang around in the atmosphere.
Is it good to pollute the abyss with suffocating liquid carbon-dioxide just so that we can make our toast in the morning and watch Survivor in the evening? No. But this is a societal problem. Society wastes energy, and uses it for foolish things.
This is a great forum for advocating changes to society, where we can see ideas or products that have much less impact on the environment. Kudos to Inhabitat, and I'm with everyone here...I dream of the evolution where we power our societies solely with the current solar capital. That will be a great society. But I think we can all agree that evolution is slow, and in the mean time we are still pumping an aweful lot of greenhouse gases into the atmosphere. It would be a good idea, for the benefit of everybody, to do "something" about those emissions right now.
I think it is entirely possible that Dr. Keith has proposed this "practical" solution (if not "palatable" solution) to climate change simply as a wake-up call to demonstrate exactly how much trouble we are in.

A totally ridiculous idea with disaster written all over it - and a fundamentaly dangerous mentality to our carbon issues.
Trying to see both sides of the story - is it that more proposterous and unlikely than some renewable energy ideas? Some theoretical 'solutions' to the energy question are equally as hollow and contain just as many potentially fatal unknowns:
http://www.inhabitat.com/2008/02/18/round-the-clock-solar-energy-from-space-solar-power-system/
But not to lose focus - this is like spraying yourself in deo instead of having a shower - at the end of the day - it still stinks.

This is a very bad idea! Storing CO2 for future generations to deal with it? Shame on you! Shifting this problem to your (and my) grandchildren! I'm really having trouble believing tha this is a serious idea, and that the people thought of the idea, are serious scientists (yes, that means you too, Keith)! Bloody idiots!

I thought that CO2 was raising Ph levels in our oceans, which is causing different types of plankton to die and corals to bleach...
But at least someone is thinking of a way to put that stuff back where we got it from.

Hmmmm - once upon a time, human kind used the oceans as a dumping ground for all their toxic waste. Tyres, nuclear waste, old ships - you name it - the oceans were our scrapyard.
Then we got smarter and realised that the oceans are a precious resource and we tried to find better ways to manage our wastes.
One fine day we found out that were also producing an evil gas as our waste, so a group of smart scientists got together to talk about solutions, and came up with the idea of dumping it all into the oceans.
"We are so clever", the scientists all cried together, and they cheered, and clapped eachother on their backs, and popped champagne because they wer all so smart, and had solved the problem.
NOT!!!!!!!!!!!!!!!
Am I not surprised that this idea came from a chemical and pertoleum engineer? I wonder which oil company pays his research dollars?
Just goes to show that there's some out there who are still looking at the problem through the same rose coloured lenses as always. Don't fix the disease - just find new (old) ways to treat the symptoms.

As a professional SCUBA Diver, preserving our underwater environment is paramount. Does anyone remember when they decided to get rid of the surplus of tires with the Osborne Reef expansion project in 1972? Military divers are still trying to get rid of those tires, nevermind all the damage the tires have caused in the past several decades.

Yet another bandaid solution. We need to stop coming up with these quick-fixes that do nothing to solve the root of the problem - our wastefulness and overconsumption. This will be a disaster waiting to happen! What about the crazy ocean currents that run along the seabed? The constant movement of ocean water due to tidal effects? There's so much we don't know about the ocean, we shouldn't be messing with it.

Jorge, I addressed a the issue of a potential underwater explosion of CO2 over at my blog. (See linked URL above.)
Long story short, due to extreme pressure and low temperatures of the average ocean depth (3800m), which is "pre-Abyssal" btw, the CO2 in the bag will be in liquid form. Therefore, any rupture will cause liquid CO2 to spill out of the bag, rather than gaseous CO2 exploding out of it.
This isn't necessarily so good, though, since - in the absence of oxygen - it will likely increase local acidity as it dissolves with the water, changing into carbonic acid. Additionally, this liquid CO2 will flow across the ocean floor, seeking out the lowest point (just like any liquid does), meaning it will suffocate any organism living on the sea floor, which just happens to be in its path.
So, I don't know if the image of an "explosion from the depths" is worse than an image of a "flowing stream of suffocating liquid", but bad news nonetheless.

Looks at first glace to be a bad idea... My take on carbon storage is that is should ideally be fixed or converted in some way - for instance stored with some form of algae that will convert the CO2 into oxygen? Whilst we're on the subject, I've heard plenty of mention of CO2 being stored in disused mines etc - does this involve it being converted into a liquid form? How does this work?